Process and apparatus for treating hydrocarbons



J. PERL Aug. 22, 1933.

PROCESS AND APPARATUS FOR TREATING HYDROCARBONS Original led e 1922Patented Aug. 22, 1933 q PROCESS AND APPARATUS FOR TREATING HYDROCARBONSJohn Perl, Tulsa, Okla., assignor to Doherty Research Company, New York,N. Y., a Corporation of Delaware Application February 4, 1922, SerialNo. 534,069

' Renewed March 5, 1929 19 Claims. (Cl. 196-58) v My invention relatesto the treatment of hyspace of the vaporizing chamber 8, preferablydrocarbon oil and more particularly to the utiliextending nearly thewhole length of said chamzation of the so called fuel oil and heavierfracber and being provided with openings therein. tions resulting fromthe commercial cracking of The vaporizing chamber 8 has a vapor dome,

petroleum. In the ordinary processes of con- 12, with baffle platestherein and is provided with 60 verting heavy hydrocarbon oils intolighter hyan outlet pipe 14 for the vapor which communidrocarbons, thereis a breaking down of the heavy Oates with suitable condenser and rundown tank saturated hydrocarbons into lighter parafiines (not shown) andis provided with a suitable reand olefines, and under the influence ofheat and iiucing valve 15 and other fittings in accordance pressure andother agencies usually present in with common practice.

commercial. processes, there is a tendency for the The bottom portionofthe vaporizing chamber olefines to polymerize, and there is also a tend-8 is provided with a pipe 16, equipped with a suitency to produce freecarbon and permanently able reducing valve 17, which opens into avaporgaseous hydrocarbons. The so-called fuel oil is izing chamber 18and is provided with a suit- 15 an intermediate product or lay-productof ordiable spraying nozzle 19 inside of said chamber 7 nary commercialtreatment of petroleum, and to spray and facilitate the evaporation ofthe here-tofore it has defied economic conversion liquid. The upperportion of this vaporizing into more desirable and lighter products.chamber 18 has a pipe 20 which communicates The principal object of myinvention is to dewith a condensing coil 21 and thence with a con- 20vise a process for the economic treatment of pe densing chamber orreceiver 22, with which are 75 troleum or hydrocarbon oils that willminimize associated a suitable level indicator 23, levelregupclymerization and enhance the production of lator 24 and floatregulated valve 25, which latter desirable and lighter products; andanother obcontrols the flow of the condensed liquid into the ject is todevise a process for the successful and storage tank 26. The bottom ofsaid vaporizing 25 economical treatment of fuel oils and the like.chamber 18 communicates by a pipe 2'7, having a 0 The invention consistsin the process and in the coiled portion 28 inside a cooling chamber 29,apparatus hereinafter described and claimed. with a constant levelsiphon chamber 30; and the In the accompanying drawing, Fig. 1represents siphon chamber is provided with a funnel-shaped an apparatussuitable for practicing my process; overflow 31 that is provided with anoutlet pipe 30 and that extends into the bottom portion of an ac- Fig. 2represents a modification thereof. cumulator tank 32 that is providedwith a suit- As illustrated in the drawing, my apparatus able levelindicator 33, level regulator 34 and comprises a furnace or heater 1, aheater coil 2 float regulated valve 35 in an outlet pipe 36 that mountedtherein and connected by a pipe 3 to a leads into a suitable storagetank (not shown).

a suitable source of supply of fresh oil and also In order to preventback pressure in the vaporconnected on the delivery side by a pipe 4 toone izing chamber 18 from disturbing the action of end chamber of aconverter or heat exchanger 5 the siphon, the upper portion of thesiphon chamwhich communicates with the opposite end ber 30 is providedwith a pipe 3'7 which communichamber thereof through a multiplicity oftubes cates with the upper portion of the receiver 22.

40 6 mounted therein in suitable tube sheets. The The condenser coil 21is preferably mounted opposite end chamber of said converter or'heat ina pipe system 38 which communicates at the exchanger is provided with adelivery pipe I which bottom through a pipe 39 with the storage tankprojects into the vapor space of a vaporizing 26 or other suitablesource of oil supply, and on chamber 8 and is provided with a series ofjet the other side it preferably communicates with 45 openings in. theportion of said pipe inside of the fresh oil supply pipe 3 that suppliesfresh oil said vaporizing chamber. The middle chamber to the heater coil2.

9 of the heat exchanger, that is, the portion be- The operation of v theabove described appatween the tube sheets and enclosing the tubes 6,ratus is as follows: The fresh oil is passed has a supply pipe 10 thatextends from the lower through the pipes 38 surrounding the condenser 50portion of the vaporizing chamber 3 into the coil 21 and there absorbsconsiderable heat from lower portion of said heat exchanger chamber, thecoil and, after this initial heating, it passes preferably near oneendthereof. A second pipe directly into the heating coil 2 of thefurnace.

11 extends from the upper portion of said heat As the primary object ofthe furnace heat is to exchanger chamber, preferably near the oppo crackthe fresh oil, it is run at a temperature suitsite end thereof, andextends into the liquid able for this. purpose, which temperature willvary more or less with the nature of the oil and the pressure in thepipe, as is well known in the art of cracking petroleum. The productsresulting from the cracking of the fresh oil in the heater pass throughthe heat exchanger 5 and into the vaporizing chamber 8. It is desirablethat the temperature of the cracked oil products at the time they enterthe exchanger shall not greatly exceed 850 F., in which case suchproductsv will enter the vaporizing chamber at a temperature in theneighborhood of 750 F. The lighter products will pass out from thevaporizing chamber through the vapor dome and the delivery line forcondensation and storage in accordance with usual practice. The productsof the cracking operation that enter the vaporizing chamber 31in aliquid form fall into the liquid space ,of said vaporizing chamber andcommingle with the other liquid therein. This liquid circulatesfrorrithe bottom portion of said vaporizing chamber to the converter or heatexchanger, where it is brought under the influence of the heat exchangertubes, that are .being heated by the cracked products fresh from theheater, and thence back into the liquid space of said vaporizer. At thesame time, a portion of such liquid is being continuously eliminatedinto the vapor space of the vaporizing chamber 18 through the nozzle 19therein; and as the pressure in the vaporizing chamber 18 isconsiderably less than that in the vaporizing chamber 8, a considerableportion of the liquid that enters the vaporizing chamber '18 willimmediately vaporize and pass off through the oil-cooled condenser 21.and thence to the storage tank. The liquid residue in the vaporizingtank 18 is drawn on by a siphonic action into the accumulator tank. Theordinary furnace temperature is in the neighborhood of 2400 F. and thetemperature of the flue gases that come in contact with the crackingcoils usually is in' the neighborhood of 1500 to 1600 .11, whereas theaverage oil temperature at the cracking phase is in the neighborhood of700 to 750 F. Under these conditions, there is a tendency to overheatthe oil in the cracking coils, especially the film of oil in immediatecontact with the metal, and thus bring about the formation of freecarbon, permanent gases and the polymerization of the olefines resultingfrom the normal cracking operation.

According to the present invention, the fresh oil is passed underpressure (say, from 100 to 500 pounds) through the cracking coils withsufficient rapidity to keep the temperature of the general mass belowthe point at which polymerization of the olefines iscaused. While theremay be some polymerization of the resulting olefines, the polymerizingaction is limited to the formation of single phase or mono-polymerides,and these are dissolved in the complex liquid and leave the heatingcoils in solution. When this complex liquid reaches the vaporizingchamber 8 and the lighter fraction thereof is drawn 011. through thevapor line, the residue becomesmore susceptible to the action of heatrso that, when such residue circulates back through the heat exchanger,its heavier components are readily broken down by the hot products ofthe cracking operation into lighter products, some of which pass off,when they reach the vaporizing chamber,

intothe vapor dome and vapor line.

As an example of the practical operation of my process, I may take ahydrocarbon oil of 32 Be. and treat it at a cracking temperature of 800F. Usually,

the fraction that is removed from the first vaporizing tank 3 throughthe vapor line is gasoline or naphtha of a gravity of about 49.8 B., andamounts to about 32 per cent. of the quantity of fresh oil treated. Theresidue is the portion that is most subject to polymerization and otherill eiiects of excessive heating; and this residue is circulated throughthe heat exchanger where it is continuously exposed to the heat of thenewly cracked products coming directly from the furnace coils at atemperature of from 800 to 850 F. This temperature is sufficient tobreak down much of the residue above mentioned but is insufiicient tobring about any considerable polymerization thereof and does not causethe production of free carbon or permanent gas in any considerablequantity. In this connection, it is noted that the heating of theresidue by thenewly cracked products is by conduction, Whereas theheating of the fresh oil in the heater coils is largely due to radiantheat, which is far more rapid and more destructive in its action onthe'oil. Thus, by treating the residue with the heat of conduction fromthe newly cracked products fresh from the furnace coils, greatuniformity of temperature is obtainable, and the breaking down of thisresidue in the heat exchanger is accomplished with economy and undervery favorable conditions for production of desirable products in largevolume and without the production of undesirable products. In theexample given, the residue above mentioned, would amount to about percent. of the initial volume of the oil, and would have an averagespecific gravity of about 21 B. in comparison with an initial gravity of32 B. of the fresh oil. As a result of the treatment above described,this residue, which passes. into the second vaporizing chamber 18, isthere separated into two fractions; one of which passes off as a vaporand is condensed into a liquid whose gravity is about B. and Whosequantity is about 38 per cent. of the original volume of the fresh oil.The other fraction is a liquid whose specific gravity is about 16 B. andwhose quantity amounts to about 25 per cent. of the original volume ofthe fresh oil.

The apparatus illustrated in Fig. 2 is especially designed for thetreatment of raw fuel oil. In this modification, the apparatus issubstantially the same as above described except that the evaporatingchamber 8 is wholly disconnected from the middle chamber of the heatexchanger 5 and its place, in this particular, is taken by an additionalvaporizing chamber 8 similarly connected and equipped. In thismodification, the middle chamber of the heat exchanger 5 is supplieddirectly from a suitable source of raw fuel oil by a supply pipe 4 andthe opposite ends of middle chamber of said heat exchanger are connectedto the vaporizing chamber 8 by means of pipes 10 and 11 especiallyprovided therefor, which vaporizing chamber is provided with a vaporoutlet line 14 and with a pipe 16 for delivering its liquid residue intothe vaporizing chamber 18 along with the residue from the evaporatingchamber 8. In this modification, the raw fuel oil is introduced from thesource of supply through pipe 4 into the middle of the heat exchanger 5where it is subjected to the heat of the freshly cracked products thatpass through the tubes therein at a temperature in the neighborhood offrom 750 to 850 degrees F. The products resulting from the heating ofthe fuel oil pass out through the pipe 11 and are delivered through thejet openings thereof into the vapor space of the vaporizing chamber 8under pressure of say, from 100 to 150 pounds. The vapors pass outthrough the vapor line in the usual way. Part of the liquid residueflows back into the mid-' dle chamber of the heat exchanger fortreatment therein, and the remainder flows into the vaporizing chamber18 either through a separate valved pipe 16 or through the same valvedpipe 16 that delivers the residue of the evaporating chamber 8. Ifdesired, the products resulting from the treatment of the fuel oil maybe kept separate from the products of the pyrogenously. cracked oil byduplicating that portion of the system illustrated in Fig. 1 throughwhich the oil passes after leaving the heat exchanger.

The operation of the apparatus illustrated in Fig. 2 is similar to thatillustrated in Fig. 1, except that the heavier fraction or first residueof the cracking of the lighter or pyrogenously cracked oil is nottreated in the heat exchanger but passes directly from the firstvaporizing chamber 8 through the reducing valve into the secondvaporizing chamber 18. While the sec ond residue may containpolymerides, they are of low order and readily soluble in the liquid andneed not be removed to fit the liquid for a base suitable formanufacturing lubricating oils. The raw fuel oil is passed through theheat exchanger, where its heavier ingredients are broken down to lighterhydrocarbons and the complex liquid containing them circulates in thevaporizing chamber 8 from which the lighter products pass off throughthe vapor dome and the vapor line. The heavier products are partlyreturned from the vaporizing chamber 8 to the heat exchanger for furthertreatment and partly pass out through the reducing valve into the secondevaporating chamber 18, where the lighter fraction thereof is evaporatedand separated from the heavier fraction. As the cracking of the fuel oilis done by the heat of conduction from the cracked products of thelighter oil, the danger of overheating the fuel oil is avoided and amaximum production of valuable products is obtained therefrom.

What I claim is:

l. The process of cracking hydrocarbon oils which comprises continuouslypassing oil stock to be cracked through a heating and cracking zone inwhich the oil is cracked at high temperature, conducting the resultinghighly-heated products while at a high temperature from said zone into aheat exchanging zone in which the highly heated products are utilizedfor indirectly heating and cracking a heavier hydrocarbon oilcontinuously passed therethrough, and separating vapors formed by theheating and cracking of the oil in said heating zones from anyunvaporized oil constituents remaining from the heating in said zones.

2; The process of treating hydrocarbons which comprises pyrogenouslycracking the same, separating the light fraction from the heavierfraction thereof under pressure, reheating the heavier fraction by theheat of the newly formed prodnets of said pyrogenous cracking andeliminating under pressure the lighter fraction thus formed, separatingthe residue into lighter and heavier fractions by evaporation underreduced pressure.

3. The process of treating hydrocarbons which comprises pyrogenonslycracking the same, separating the light fraction from the heavierfraction thereof under pressure, circulating the heavier fractionthrough a heat exchanger heated by the hydrocarbons fresh from thepyrogenous cracking operation and eliminating under pres-. sure thelighter fraction thus formed, and separating the residue into lighterand heavier fractions by evaporationunder reduced pressure.

4. The process of treating hydrocarbons which comprises the pyrogenouscracking thereof in a continuous stream, passing the entire stream ofresulting products through a heat exchanger and thence to an evaporatingchamber wherein pressure is maintained, eliminating from said evapcrating chamber under pressure the lighter fraction resulting from thecracking of said hydrocarbons, passing part of the heavier fractionthrough said heat exchanger out, of contact with the stream of newlyformed products and back to said evaporating chamber, withdrawing fromsaid evaporating chamber a portion of the heavier content thereof andeliminating its lighter fraction from said portion under a pressurelower than that of said evaporating chamber.

5. Apparatusjfor treating hydrocarbons comprising a heating coil, a heatexchanger having one of its chambers connected with said heating coil;an evaporating chamber connected with said chamber of said heatexchanger to receive the hydrocarbons thereof, a second evaporatingchamber connected to said first evaporating chamber, and a reducingvalve in the connection between said chambers, said evaporating chambershaving vapor outlet lines and said second chamber having a line fordelivering the liquid residue therefrom, and means for circulating oilfrom said first mentioned evaporating chamber through a second chamberof said heat exchanger to be heated thereby without commingling with thesupply direct from the heating coil and thence back to said firstmentioned evaporating chamber.

6. Apparatus for treating hydrocarbons com prising a heating coil, aheat exchanger connected therewith, an evaporating chamber connectedwith said heat exchanger to receive the hydrocarbons therefrom, a secondevaporating cham-, ber connected to said first evaporating chamber, anda reducing valve in the connection between said chambers, saidevaporating chambers hav ing vapor outlet lines and said second chamberhaving a line for delivering the liquid residue therefrom, and means forcirculating oil through said heat exchanger to be heated thereby, saidmeans comprising pipe connections between said heat exchanger and theliquid space of said first mentioned evaporating chamber.

7. Apparatus for treating hydrocarbons comprising a heating coil, a heatexchanger connect ed therewith, an evaporating chamber connected withsaid heat exchanger to receive the hydrocarbons-therefrom, a secondevaporating chamber connected to said first evaporating chamber, and areducing valve in the connection between said chambers, said evaporatingchambers hav-- ing vapor outlet lines and said second chamber having aline for delivering the liquid residue therein, and means forcirculating oil through said heat exchanger to be heated thereby, saidmeans comprising a supply pipe for supplying the oil to be heated tosaid heat exchanger and an outlet pipe for such oil extending from saidheat exchanger to a third evaporating chamber.

8. Apparatus for treating hydrocarbons comprising a heating coil, a heatexchanger connected therewith, an evaporating chamber connected withsaid heat exchanger to receive the hydrocarbons therefrom, a secondevaporating chamber connected to said first evaporating chamber,

and a reducing valve in the connection between said chambers, saidevaporating chambers having vapor outlet lines and said second chamberhaving a line for delivering the liquid residue therein, and means forcirculating oil through said heat exchanger to be heated thereby, saidmeans comprising a supply pipe for supplying oil to be heated to saidheat exchanger .from' said first mentioned evaporating chamber and anoutlet pipe for such oil extending from said heat exchanger to saidfirst mentioned evaporating chamber.

9. The process of cracking petroleum oil, which comprises passing theoil to be treated through a heating zone wherein the oil is heated tocracking, conducting the highly heated products from said heating zonethrough a heat exchange zone and into a vaporizing .zone, and

passing unvaporized oil from said last mentioned zone through said heatexchange zone to be heated by said highly heated oil by indirect heatexchange therewith.

10. The process of cracking hydrocarbon oils, which comprises heatingoil to a cracking temperature in a heating zone and passing it through aheat exchange zone and then into a vaporizing zone maintained under asuperatmospheric pressure, conducting unvaporized oil from said lastmentioned zone through said heat exchange zone and returning the same tosaid vaporizing zone, withdrawing residuum from said vaporizing zoneinto a second vaporizing zone maintained under a lower pressure thansaid first-mentioned vaporizing zone and vaporizing substantialquantities of said residuum therein, conducting vapors from said secondvaporizing zone to a condenser, and passing the resulting condensateinto the heating zone, for conversion into lower boiling products. y

11. The process of converting higher boiling hydrocarbons into lowerboiling products, which comprises heating and cracking a high boilingoil in a heating zone, conducting the resulting oil through a heatexchange zone and theninto a vaporizing zone, passing unvaporized oilfrom said vaporizing zone through said heat exchange zone to furtherheat and crack the same, passing unvaporized residue from said crackingoperations into a residue vaporizing zone maintained under a lowerpressure than said first mentioned vaporizing zone and vaporizingsubstantial quantities of said residue therein, condensing the vaporsproduced in said residue vaporizing zone and passing the resultingcondensate into the said heating zone.

12. The process of converting hydrocarbon oils into lower boilingproducts, whichcomprises heating and cracking a hydrocarbon oil in aheating zone and conducting it while at a high temperature through aheat exchange zone, passing a heavier hydrocarbon oil in indirect heatexchange with the highly heated oil in said heat exchange zone therebyto heat and crack said heavy hydrocarbon oil, and vaporizing portions ofsaid cracked oils by introducing the same into a vaporizing zonemaintained under a pressure lower than the pressure maintained on theoil during said cracking.

13. In the pyrogeneous cracking of petroleum oils; the process whichcomprises maintaining a body of oil in an enlarged cracking chamber at acracking temperature and under a superatmospheric pressure, passing oilfrom said chamber through ,a heating zone and back to said chamber,withdrawing portions of the oil from said chamber into a vaporizingzone. main tained under a lower pressure than that maintained in saidchamber and vaporizing substantial portions of the oil introduced intosaid zone, condensing a stock for recracking from the vapors formed insaid vaporizing zone by passing them in heat exchange with condensatepreviously, formed from the vapors from said vaporizing zone, heatingsaid stock in a second heating zone to a high cracking temperature,utilizing. the resulting highly heated products for indirectlyheatingthe oil from said chamber in said first-mentioned heating zone,and introducing the'said'products into said enlarged chamber.

14. The process of cracking hydrocarbon oils, which comprises passingoil in a closed cycle from an enlarged body of oil in a cracking zonethrough a heating zone in which the oil is heated to a crackingtemperature and .then back into said cracking zone, thereby to maintainsaid body of oil at a cracking temperature, maintaining the oil of saidbody under a substantial superatmospheric pressure, withdrawing residuumfrom said body into a vaporizing zone maintained under a lower pressurethan the pressure maintained on the oil of said body and in whichvaporization of substantial portions of said residuum is effected by theheat contained therein, condensing the vapors evolved from saidresiduum, passing the condensate produced from said vaporsthrough aseparate heating zone in which it is heated to a cracking temperature,and passing the resulting products into said cracking zone.

15. The process of cracking hydrocarbon oils, which comprises passingoil in a closed cycle from an enlarged body of oil in a cracking zonethrough a heating zone in which the oil is heated to a crackingtemperature and then back into said cracking zone, thereby to maintainsaid body of oil at a cracking temperature, maintaining the oil of saidbody under a substantial superatmospherie pressure, withdrawing residuumfrom said body into a vaporizing zone maintained under a lower pressurethan the pressure maintained on the oil of said body and. in whichvaporization' of substantial portions of said residuum is effected bythe heat contained therein, condensing the vapors evolved from saidresiduum, passing the condensate produced from said vapors through asecond heating zone in which it is heated to a cracking temperature, andpassing the resulting products while in a highly heated state in heatexchange but out of direct contact with the oil being passed throughsaid closed cycle and then into a second enlarged cracking zone.

16. The process of cracking relatively heavy hydrocarbon oils, whichcomprises passing such oil through a heating zone in which the oil isheated to a cracking temperature, passing the resulting products into anenlarged cracking zone in which vapors are separated from unvaporizedoil residuum, maintaining a substantial superatmospheric pressure on theoil constituents in said enlarged zone, Withdrawing reisduum from saidenlarged zone into a reduced pressure vaporizing zone in whichsubstantial portions of the residuum introduced thereinto are vaporizedby heat contained therein, condensing vapors formed from said residuum,passing the resulting condensate through a second heating zone in whichit is heated to a high cracking temperature, passing the resultingproducts from the heating of said condensate while in a highly heatedstate in indirect heat exchange with the oil passing through thefirst-mentioned heating zone and then into a second enlarged crackingzone in which vapors are separated from unvaporized oil, maintaining asubstantial superatmospheric pressure in said second enlarged zone,withdrawing unvaporized oil constituents from said second enlarged zoneinto said reduced pressure zone, and therein vaporizing substantialportions of the unvaporized oil to aid in supplying said condensate.

1'7. The process of cracking hydrocarbon oils, which comprises passingan oil distillate cracking stock in a confined stream through a heatingzone, heating the said stock in said zone to a cracking temperature andcracking the same while in said zone, passing the highly heated productsof said stock from said zone into heat exchange but out of directcontact with relatively heavy fresh oil charging stock thereby tosubstantially cool the products from said zone and heat said heavy freshoil stock to a temperature suflicient to vaporize substantial portionsthereof, passing the products cooled by said heat exchange into anenlarged vaporizing zone, vaporizing portions of said fresh oil stockheated by said heat exchange, condensing the said vaporized portions toform a distillate suitable as a cracking stock and conducting the sameto said heating zone to form at least in part the said distillatecracking stock for said zone.

18. In the pressure distillation of oils heavier than gasoline for theproduction of gasoline-like products, forcing oil through a heating zoneinto a maintained pool, thereby bringing the oil to conversiontemperature and maintainingthe pool at conversion temperature,discharging liquid products from said pool to another pool, removing oilcontinuously from the latter pool, the oil passing from the heating zoneto the first pool being led in a confined stream and through the latterpool in indirect heat conductive relationship with the liquid contentsthereof.

19. The process of pyrogenously cracking petroleum oils which comprisesheating and cracking the oil under superatmospheric pressure, passingthe resulting highly heated liquid and vapor products through a coolingzone and then into a separating zone where vapors and liquid productsare separated and wherein a substantial body of oil is maintained undercracking conditions of temperature and pressure, conducting portions ofthe liquid products directly from said separating zone back into saidcooling zone in indirect heat exchange with the highly heated oilconstituents passing therethrough, thereby to reheat and effectdistillation of portions of the liquid products returned to said coolingzone.

JOHN PERL.

